Sam (xraytech):
<i."Maybe Sandy can help me with what anniversary model I have and what year it is from."</i>
Sounds like yours could be a C-5, a C-6 or a C-7; all of these models were turquoise (not to be confused with earlier and later models that were blue). Does yours have two wheels in back, with two bumps at the front end of the bottom- the end where the hose attaches? Or is it three wheels- one in the front and two in the back? Or does it have four wheels?
With two wheels, you have a C-5, made between 1959-1960, according to the TriStar website. The three-wheeler is the C-6, made from 1961-1970. The four-wheeled C-7 was made from 1971-1972.
A "25th Anniversary" machine would likely be either a C-6 or a C-7. There are three ways that Interstate could calculate an anniversary date. One is the 1937 founding of the company as an aircraft manufacturer. Another is the 1940 date of the introduction of the first Compact, which you can see on Charles Lester's website,
www.137.com. Another is the 1946 introduction of the Compact C-1; this was the first machine that really sold in substantial numbers (the 1940 Compact didn't really get off the ground before WWII disrupted production).
Anyway, counting 25 years from 1937 would give you 1962, which is two years after the last date for the C-5 (two wheels), so you can probably discount that one completely. 1962 would be a good fit for the C-6 (three wheels). Counting 25 years from 1940 would give you 1965, which would also fit the C-6. Counting 25 years from 1946 would give you 1971, which would fit the C-7 (four wheels).
If this helps, please tell us which machine you have; it would help to know which one Interstate called the 25th Anniversary machine. The TriStar website only shows the left (emblem) side for most machines; their decals went on the right side, so there's no way to tell which was the 25th Anniversary machine from the website.
